MDEV-8453 Alter table not returning engine errors

remove ~15 years old print_lock_error() function, use
handler::print_error() instead

Backport from 10.1

mysql-test/r/engine_error_in_alter-8453.result

+create table t1 (a int, b int);
+set debug_dbug='+d,external_lock_failure';
+alter table t1 add column c int;
+ERROR HY000: Got error 168 'KABOOM!' from MyISAM
+set debug_dbug='';
+drop table t1;

mysql-test/t/engine_error_in_alter-8453.test

+#
+# MDEV-8453 Alter table not returning engine errors
+#
+--source include/have_debug.inc
+
+create table t1 (a int, b int);
+set debug_dbug='+d,external_lock_failure';
+--error ER_GET_ERRMSG
+alter table t1 add column c int;
+set debug_dbug='';
+drop table t1;

sql/handler.cc

@@ -3650,6 +3650,8 @@ void handler::print_error(int error, myf errflag)
 */
 bool handler::get_error_message(int error, String* buf)
 {
+  DBUG_EXECUTE_IF("external_lock_failure",
+                  buf->set_ascii(STRING_WITH_LEN("KABOOM!")););
   return FALSE;
 }
 
@@ -5944,6 +5946,8 @@ int handler::ha_external_lock(THD *thd, int lock_type)
   MYSQL_TABLE_LOCK_WAIT(m_psi, PSI_TABLE_EXTERNAL_LOCK, lock_type,
     { error= external_lock(thd, lock_type); })
 
+  DBUG_EXECUTE_IF("external_lock_failure", error= HA_ERR_GENERIC;);
+
   if (error == 0 || lock_type == F_UNLCK)
   {
     m_lock_type= lock_type;

sql/lock.cc

@@ -92,7 +92,6 @@ extern HASH open_cache;
 
 static int lock_external(THD *thd, TABLE **table,uint count);
 static int unlock_external(THD *thd, TABLE **table,uint count);
-static void print_lock_error(int error, TABLE *);
 
 /* Map the return value of thr_lock to an error from errmsg.txt */
 static int thr_lock_errno_to_mysql[]=
@@ -358,7 +357,7 @@ static int lock_external(THD *thd, TABLE **tables, uint count)
 
     if ((error=(*tables)->file->ha_external_lock(thd,lock_type)))
     {
-      print_lock_error(error, *tables);
+      (*tables)->file->print_error(error, MYF(0));
       while (--i)
       {
         tables--;
@@ -675,8 +674,8 @@ static int unlock_external(THD *thd, TABLE **table,uint count)
       (*table)->current_lock = F_UNLCK;
       if ((error=(*table)->file->ha_external_lock(thd, F_UNLCK)))
       {
-	error_code=error;
-	print_lock_error(error_code, *table);
+        error_code= error;
+        (*table)->file->print_error(error, MYF(0));
       }
     }
     table++;
@@ -898,36 +897,6 @@ bool lock_object_name(THD *thd, MDL_key::enum_mdl_namespace mdl_type,
 }
 
 
-static void print_lock_error(int error, TABLE *table)
-{
-  int textno;
-  DBUG_ENTER("print_lock_error");
-
-  switch (error) {
-  case HA_ERR_LOCK_WAIT_TIMEOUT:
-    textno=ER_LOCK_WAIT_TIMEOUT;
-    break;
-  case HA_ERR_READ_ONLY_TRANSACTION:
-    textno=ER_READ_ONLY_TRANSACTION;
-    break;
-  case HA_ERR_LOCK_DEADLOCK:
-    textno=ER_LOCK_DEADLOCK;
-    break;
-  case HA_ERR_WRONG_COMMAND:
-    my_error(ER_ILLEGAL_HA, MYF(0), table->file->table_type(),
-             table->s->db.str, table->s->table_name.str);
-    DBUG_VOID_RETURN;
-  default:
-    textno=ER_CANT_LOCK;
-    break;
-  }
-
-  my_error(textno, MYF(0), error);
-
-  DBUG_VOID_RETURN;
-}
-
-
 /****************************************************************************
   Handling of global read locks